Note: Descriptions are shown in the official language in which they were submitted.
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PACKAGING MATERIAL AND METHOD FOR MICROWAVE AND STEAM
COOKING OF PERISHABLE FOOD PROD UCT
CROSS REFERENCE TO RELATED APPLICATION
The instant application claims priority under the Patent Cooperation Treaty
(PCT)
Article 8 and Rule 4.10 to the U.S.A. Patent Application Serial Number
10/855,305,
filed on May 27, 2004, which is herein incorporated by reference in its
entirety.
FIELD OF THE INVENTION
The present invention generally relates to the field of packaging for
perishable food
products, and particularly to a package and method of packaging perishable
food
products which optimizes the food product life, provides the food product in a
ready
to eat form, and allows for cooking of the food product.
BACKGROUND OF THE INVENTION
Tropical fruits, such as bananas, are grown largely in developing countries,
harvested
at their mature green stage (color stage 1-1.5), packed in 40 lb. cardboard
boxes, and
then transported in temperature controlled ships thousands of miles around the
Atlantic and Pacific oceans before reaching the consumption markets of the
United
States, United Kingdom, Japan, and other emerging Far East markets.
Once the fruit arrives in the destination market, it is typically artificially
ripened in
temperature controlled commercial ripening rooms (still in cardboard boxes)
with
exogenous application of a ripening hormone, ethylene. Depending on the
temperature of the ripening room (56 to 64 F), ripening to color stage 3.5
can take 4
to 6 days. Super market chains and food service outlets then typically
purchase
banana fiuits from distributors once the fruit has reached color stage 3.5.
The fruit is typically pulled,out of the 40 lb. cardboard boxes and displayed
on
supermarket shelves at or post color stage 3.5. Interestingly, the further
progression
of banana fruit ripening is quick and in most cases it takes only 2 to 3 days
to reach
color stage 7. The fruit at color stage 7 has well-developed sugar spots and
market
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tolerance to such fruits is zero. Thus, the marketing window for supermarkets
is
typically only 2 to 3 days. Because of the resulting short market life of
bananas,
supermarkets are constantly advertising marketing promotions to minimize fruit
losses at the supermarket level.
While supermarkets on the one hand want to move the banana fruit quickly out
of
their store, consumers on the other hand are not eager to purchase any
additional fruit
quantities beyond their two to three day fruit needs. Consumers often handpick
fruits
that they perceive will last for at least a few days. They physically color
sort and pick
the fruits and in doing so some damage to the fruit is induced by customers.
This
leads to around 10% shrinkage at supermarket level.
Consumers often purchase from four to ten fruit in a single hand, all of which
ripen
simultaneously. Very often, only one or two fruit are consumed at the
consumer's
preferred stage of ripeness. Bananas commonly become overripe and are eaten at
this
lower level of quality or are often discarded or directed into a use other
than fresh
consumption (e.g., purees or baked products). Although preservation post color
stage
3.5 continues to be the problem, consumers demand high quality bananas in the
marketplace.
Supermarkets have evolved to play a dominant role in meeting consunier
expectations. They recognize that one of the ways to reduce shrinkage at the
supermarket level is to offer bananas in 1 to 3 lb. consumer packages. This
concept
has completely evolved in the European markets and the need for packaged fruit
in
the United States is growing. Currently, approximately 10% of the total United
States
market demand is sold in 3 lb. packages. In some instances, due to the high
respiration needs of banana, currently used packages are macro perforated
(sixteen to
twenty 1 cm diameter holes/package) and do not offer any quality protection or
extension of shelf life.
There is a commercial interest in extending and preserving the market
preferred
yellow life of bananas. Extension of green life of bananas by use of
controlled
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atmosphere (Mapson and Robinson, 1966, McGlasson and Wills, 1972; Madrid and
Lopez-Lee, 1998) or modified atmosphere (Mapson and Robinson, 1967; Burg,
1975;
Yahia, 1997) has been achieved to some extent. However, these technologies may
lead to alteration of ripening characteristics of banana fruit that may lead
to dull
yellow color and slow ripening in air. In addition, the delayed ripening to
color stage
3.5 is significantly increased such that fruit ripening is difficult to manage
at the
commercial level.
Further, U.S. Patent Application Number 2002/0127305 Al uses a porous patch
consisting of side-chain-crystallizable acrylic polymers for storage and
ripening of
green bananas. The polymer is designed to undergo a phase transition; the
polymer
molecules shift from a somewhat ordered, more crystalline state (less
permeable) to a
more amorphous state (more permeable) as the temperature rises. Thus, the
patch
made up of this special polymer is the major route for gas flow in and out of
the
package. The physical properties of these polymers are such that they are not
suitable
as packaging material but rather are suited as patches applied to packages. In
order
for this technology to work for the banana industry, one must drill the hole
on the bag
and apply the breathable patch over the hole before the fruit is packed in
such an
invention. These extra steps reduce the pack-out speed that directly
translates to the
higher packing cost per unit of packed fruit. In addition, this technology is
very
expensive.
U.S. Patent Number 6,190,710 B 1 describes a method of preserving produce
utilizing
special polymers such as XTEND (StePac L.A. Ltd., Israel) that are designed
to
facilitate moisture loss to minimize condensation and decay development. These
films are based on copolymers of polyester and polythene, which have the
advantage
of high transmission of water vapor, thus enabling the humidity to diffiise
out of the
package before the water droplet is formed. However, the permeance of the fihn
to
oxygen is too low, such that the film needs to be perforated in order to
prevent
anaerobiosis and the production of off-flavors by the product. The authors
used
special polymer bags in conjunction with relatively large perforations of 600
diameter to prevent decay of 12 kilogram banana bunches. The specialized
polymers
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used to achieve decay control are, again, very expensive.
Compared to other tropical fruits, the quality standards for marketing of
bananas are
relatively high. One of the drivers of banana sales is their good appearance.
An
attractive, bright and clean display of high quality, blemish-free and well-
colored fruit
promotes sales. Display of green or bruised bananas is viewed as a significant
detraction by supermarket chains. Unfortunately, most of the currently
available
technologies including sealed non-perforated and perforated polymeric packages
do
interfere with the display quality of banana fiuit.
The general dogma of extending storability by modified atmospheric packaging
("MAP") is that storability will improve in response to low 02 package
atmospheres.
However, it is important to recognize that while low 02 atmospheres can
improve
storability of some fruits and vegetables, it has the potential to induce
undesirable
effects as well. If 02 levels decline below concentrations required to sustain
aerobic
respiration, fermentation and off-flavors may result (Kays, 1997; Richardson
and
Kosittrakun 1995). Risks include not only the loss of product quality through
fermentative metabolism, but also the growth of potential human pathogens that
thrive
under anaerobic conditions (Hintlian and Hotchkiss, 1986; Nguyen-the and
Carlin,
1994). In addition, fermentation can lead to development of CO2 concentrations
exceeding a level tolerated by the plant tissues and thereby causing injury to
the plant
tissue. Tolerance limits for 02 and COa for bananas are above 2% 02 and below
7%
CO2. Surprisingly, for bananas, it has been discovered that the tolerance
limits to COa
increased to 20% if the package 02 increased to 6%. Incorporation of high CO2
in the
packaging not only protects the product quality but also suppresses the
microbial
growth and development.
Fruits and vegetables have been receiving considerable attention as consumers
become more health conscious. Health benefits associated with regular
consumption
of fresh fruits and vegetables such as blueberries, cranberries, strawberries,
apple,
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carrots, broccoli and tomato are generally well recognized (Djuric and Powell,
2001;
Kays, 2001).
Health conscious consumers are increasingly spending more on fresh produce,
and are
5 buying new value-added fresh-produce products (Dimitri et al., 2004). Value-
added
fresh-produce products include fresh-cut fruits and vegetables, such as
carrots,
broccoli, cauliflower, corn, leafy greens, strawberries, blueberries, apple,
grapes,
cranberries etc., which are offered for sale in a pre-packaged form. This type
of
value-added benefit, which provides the product in a Ready-to-Eat form, may
allow
the product to be cooked while still within the package and/or allow the
product to be
distributed and stored in various Ready-to-Eat forms, such as pre-packaged
salads,
pre-packaged baby carrots, pre-packaged strawberries, and the like.
The US produce market is estimated at about $88 billion and these value-added
products comprise the most rapidly growing segment of the fresh produce
industry as
well as one of the most rapidly growing categories in the supermarket and food
service markets. This growth is evidenced by facts, such as that the
corisumption of
value-added produce has increased from $82 million in 1989 to $10 billion in
2003
(Center for Nutrition Policy and Promotion) accounting for over 10% of produce
sales. The value-added segment of the US produce market is expected to reach
approximately $25 billion over the next five years, with the food service
market alone
accounting for 20% or $5 billion. Fast food restaurants, supermarket chains,
and food
service brokers are expected to fuel the continued growth of this market
sector.
Further, "The Packer's Food Trends" estimate that eight out of ten domestic
consumers bought pre-packaged (value-added) salads in 1995. Further,
estimations
indicate that approximately 75% of all US households are 'regular' purchasers
of pre-
packaged (value-added) produce at least once a month. Additionally, the
percentage
of health conscious consumers is increasing, as more and more consumers demand
healthier, safer, and environmentally friendly food products. Concurrently,
the
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consumer recognizes the functional properties of produce, such as lycopene in
tomato
and other anti-carcinogenic compounds in many fruits and vegetables.
In addition to increased fruit and vegetable consumption, the demand for high
quality,
variety and convenience of fresh produce products has also increased. The
explosion
in produce department offerings in supermarkets evidences this trend. For
instance,
the entry of premium priced greenhouse vegetable products into US supermarkets
from Spain, Israel, The Netherlands and Canada provide an indication that the
consumer is looking for premium quality produce and may be willing to pay the
associated premium price. As described previously, this growing market demand
has
resulted in the fresh-cut fruit and vegetable industry experiencing
significant growth
over the past few years.
One of the major factors contributing to successfully increasing consumption
of fruit
and vegetables is delivering products with good quality. Efforts to maintain
the
quality of lightly processed perishable products (fresh fruit and vegetables)
throughout the processes of distribution and storage has focused on modifying
or
controlling the internal atmospheric environment provided by the packages
within
which these products are distributed and stored. The atmospheric modification
which
takes place in packages may be dependent upon several variables such as
permeability
of the material of the package, respiration rate of the perishable product and
temperature during distribution and storage. Currently, there are techniques
which
attempt to modify or control the atmosphere within the package(s) containing
these
products. Typically, these controlled atmosphere packaging devices utilize
regimes
similar to those of controlled-atmosphere storage. Unfortunately, these
controlled-
atmosphere regimes may not provide optimal atmospheric conditions within the
package for the various products during their distribution and storage, which
may
result in premature fermentation (degradation) of the product within. This
premature
fermentation may result in decreased shelf-life of the perishable food
products which
in turn may result in decreased sales of the products.
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Further, the current modified atmosphere technology may not allow for the food
product to develop to a desired ripeness, providing a certain aesthetic, in a
time
sensitive manner and then be maintained at the desired ripeness for a
prolonged
period of time. For instance, the distribution and storage of bananas is
influenced by
a color scale from 1 to 7. At a desired ripeness the bananas are typically at
3-4 on the
color scale presenting an aesthetic of a yellow banana peel with few or no
discolorations. The discolorations are indicative of the fermentation
(degradation) of
the banana fruit and as they increase in appearance, the sale of such bananas
may
decrease. Bananas are typically distributed and stored in packaging devices,
therefore
having a packaging device which was able to assist in prolonging the banana
fruit at
the desired ripeness indicated by a color appearance of 3-4 would be
desirable.
The Ready-to-Eat packaging devices mentioned above may provide a simplified
meal
alternative or may allow for the cooking of the produce within. Current
technology
provides packaging devices which allow the package, including the product
within, to
be steam cooked, such as within a microwave oven. Unfortunately, this type of
packaging may not employ any modified atmosphere capabilities or simply employ
those which are currently known and do not optimize product life. Therefore,
fermentation (degradation) of the food product may result after a shortened
product
life making the product aesthetically undesirable and possibly nutritionally
compromised.
Therefore it would be desirable to provide a packaging device and method of
packaging fresh produce which allows the produce to maintain excellent quality
and
shelf life during distribution and may also allow the fresh produce to be
cooked (i.e.,
steam cooked) in situ, allowing maximum quality and nutrient retention.
SUMMARY OF THE INVENTION
3o Accordingly, the present invention provides a packaging device for fresh
produce,
such as fruits and vegetables, which provide low oxygen and high carbon
dioxide
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regimes which are able to maintain desired atmospheric conditions within the
package
throughout the distribution and storage of the fresh produce within the
package. In a
first aspect of the present invention, a packaging device, modified atmosphere
packaging (MAP), is provided. The packaging device provides for the enclosure
of
food products, such as fresh produce, in polymeric films in which the gaseous
environment is actively or passively altered due to the presence of micro-
perforations
to affect respiration, reduce decay (inhibit fermentation), and/or extend the
shelf life
of the food products. It is an object of the present invention to employ the
packaging
device for use with various food products, such as meat products, that may be
stored
alone in the packaging device or in combination with various other food
products.
It is also an object of the present invention to provide a packaging device
including
micro-perforations which promote the cooking of a perishable food product
while
stored within the packaging device. It is also an object of the present
invention that
the micro-perforations included within the packaging device do not
substantially alter
the cooking properties of the packaging device.
It is a further object of the present invention to assist in increasing the
ease of use of
the food product, such that the food product is ready for use (Ready-to-Eat)
upon
delivery. The ready for use aspect of the present invention allows the present
invention to provide food products in a form which provides a consumer of the
food
product the ability to consume the food product straight from the package or
to heat
and/or cook the food product within the package. In addition, the present
invention
may provide less waste at a food service location as the deliverable food
product may
be portioned for use. It is yet another object of the present invention to
provide for
flexibility and customizability of packaging upon demand by a consumer.
With respect to the food service industry it is an object to assist in
promoting the ease
of use of the food product, by process employees (people who prepare the food
product), as the food product provided within the packaging device may not
require
preparations, such as slicing, cutting, or washing of the food products before
the food
product may be transferred to another container for cooking. Additionally, the
present
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invention may allow for increased integration of other menu items (food
products)
emphasizing alternative food options.
With regard to a first aspect of the invention, microperforated packaging is
provided
that creates package environments (C02, 02, ripening agent, and H20 Vapor)
that
interact in a synergistic fashion to maintain the quality of fiuit at the
desired maturity
stage and to insure that when the ripening progresses, all of the desired
sensory
attributes develop as expected. This helps to increase the utility and quality
of high-
respiring and climacteric fruits (i.e., fruits that produce and respond to a
ripening-
related gas, such as the ripening hormone ethylene) by allowing the
distributors to
initiate ripening and control ripening with improved quality during transport,
distribution, marketing, and/or consumption. This also helps the banana
industry
increase the product offerings of bananas to the retail and food service
outlets by,,
extending the shelf life of different maturity bananas, potentially all but
more
specifically those within the color range of 3 - 7.
With regard to another aspect of the invention, a process is disclosed of
packaging
perishable food product, and in a particularly preferred embodiment, bananas,
in
which 02, CO2, ripening agent (e.g., ethylene), and moisture within a package
modulate ripening and storability of the food product. Package atmospheres
comprising high levels of CO2 and H20 vapor, and moderate levels of 02 and
C2H4
(or other ripening agents) provide useful synergy in the extension of banana
shelf life
of all color stages and retention of quality attributes during distribution,
marketing,
and/or consumption. While the examples set out below particularly reference
the use
of ethylene as the ripening agent, it should be noted that appropriate
ripening agents
may also include analogs of ethylene, such as (by way of example) propylene.
The packaging and method of packaging comprising the invention herein provide
a
cost effective quality preservation process for packing, handling, ripening,
3o distribution, marketing, and/or consumption of banana fruit. More
particularly, the
packaging and method of packaging pursuant to the preferred embodiments of the
instant invention set forth herein provide for the preservation of perishable
food
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product, and more particularly bananas, by recognizing and accounting for the
commercial importance of color stage 3.5 in the ripening protocol and the need
to
further preserve the marketable (color stage 3.5 - 6.0) and consumer-preferred
eating
quality (color stage 5.0 - 6.5). Microperforated packaging is used to create
package
5 environments that do not appreciably delay ripening to color stage 3.5, but
that
significantly delay ripening post color stage 3.5 for commercial needs, while
maintaining highly uniform color and sensory attributes of the fruit, and
delaying and
even inhibiting the onset of sugar spot development.
10 The packaging and method of packaging of the instant invention allow the
use of a
low cost polyethylene bag, and do not interfere with the established protocols
of
packing, transport, ripening, distribution, and marketing protocols for
bananas. In
addition, the packaging and method of packaging of the instant invention
extends
yellow life, maintains peel integrity, delays onset of sugar spots, and/or
inhibits
considerably further progression of sugar spot development.
It is to be understood that both the foregoing general description and the
following
detailed description are exemplary and explanatory only and are not
restrictive of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric illustration of a packaging device including a
plurality of
micro-perforations in accordance with an exemplary embodiment of the present
invention.
FIG. 2 is an illustration of the packaging device of FIG. 1, wherein the
packaging
device is sealed about a perishable food product stored within.
FIG. 3 is an illustration of a packaging device in the configuration of a lid
stock
including micro-perforations for connection with a tray in accordance with an
exemplary embodiment of the present invention;
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FIG. 4 is an illustration of the lid stock of FIG. 3 connected with and
sealing the tray
including a perishable food product.
FIG. 5 is an illustration of a roll stock including a plurality of micro-
perforations in
accordance with an exemplary embodiment of the present invention.
FIG. 6 is an isometric illustration of a packaging device in the configuration
of a
stand-up pouch including micro-perforations in accordance with an exemplary
embodiment of the present invention;
FIG. 7 is a block diagram illustration of a method of cooking a perishable
food
product using a packaging device including micro-perforations in accordance
with an
exemplary embodiment of the present invention.
FIG. 8 is a block diagram illustrating a method of prolonging the shelf-life
of a
perishable food product.
FIG. 9 is a block diagram illustration of a method of providing a Ready-to-Eat
perishable food product in accordance with an exemplary embodiment of the
present
invention.
FIG. 10 is a graphical representation of the effect of the invention on a 4
day ripening
of perishable food products.
FIG. 11 is a graphical representation of the effect of the invention on a 4
day ripening
followed by 5 day storage of perishable food products.
FIG. 12 is a photograph comparing the physical state of food product that had
been
packaged according to the invention in contrast to the same food product that
had
been packaged via conventional means.
DETAILED DESCRIPTION OF THE INVENTION
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The present invention provides a packaging device for a perishable food
product, such
as fruits and vegetables, which assists in optimizing quality and shelf-life
of the
perishable food product. It is also contemplated that the packaging device may
be
used for storing and distributing perishable meat products. The packaging
device
accomplishes this optimization by providing a desired interior atmosphere
(where the
perishable food product is located) for the storage and distribution of the
perishable
food product. It is contemplated that the perishable food products are non-
frozen
perishable food products. Further, the packaging device allows the cooking of
the
perishable food product while contained within. For example, the packaging
device
lo including the perishable food product within may be positioned for steam
cooking
within a nlicrowave oven. Other cooking techniques as contemplated by those of
ordinary skill in the art may be employed for cooking the perishable food
product
within the packaging device of the present invention.
The packaging device, or modified atmosphere packaging-(MAP) system, provides
a
web for at least partially encompassing a perishable food product within, that
may be
constructed using one or more polymeric base films and in various
configurations.
For example, the web may be constructed as a bag, lid stock, stand-up pouch,
and the
like. It is contemplated that the base films may be any one of or combination
of
polymer groups such as polyalkenes (e.g., polyethylene - low density, low
linear
density, high density, etc.), polyvinyls (e.g., polypropelene), polystyrenes
(e.g.,
polyvinyl chloride), polysiloxanes (e.g., silicone rubber), and polydiens
(e.g., natural
rubber). Further, the base film may be extruded from a single polymer or
blends of
various polymers where each polymer performs a specific function, such as
contributing strength, transparency, sealability, or machineability, to meet
specific
product requirements. Similarly, the material(s) of the base film may be
processed
using various technologies and treatment applications, such as lamination, to
provide
the packaging device with specific properties and for achieving particular
configurations.
In a preferred embodiment shown in FIGS. 1 and 2, a packaging device 100 (MAP
system) is in a bag configuration using heat sensitive polymeric base fihns
bonded
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(i.e., laminated) together, which further provide a venting system for
releasing
pressure during a cooking process (i.e., steam cooking). Thus, it is
understood that
the packaging device 100 includes cooking properties which allow it to be used
for
the distributing, storing and cooking of a perishable food product. In the
current
embodiment, the packaging device 100 includes a first base fihn 105, which is
made
from a cast poly-propylene (CPP), that is bonded (laminated) to a second base
film
110, which is made from a polyethylene terephthalate (PET). It is to be
understood
that the first and second base film may be constructed from various materials,
such as
those previously mentioned. The first base film 105 may be constructed
generally in
a standard bag configuration. For instance, the first base film 105 may
provide a web
where the sidewall is constructed from connecting the ends of a continuous
piece of
material, thereby constructing opposing sidewalls of a bag. Further, the top
and
bottom edges may be joined together and may include gusseting. This connection
of
the continuous piece of material and joining of the edge(s) provides the bag
with an
outer surface exposed to an exterior (ambient) environment and an inner
surface
which defines an interior space allowing for the storage of food products
within and
between the opposing sides of the inner surface. From Example 1, described
below,
the packaging device 100 or "bag" may be one hundred twenty one millimeters
(121mm) wide with additional gusset width of approximately thirty-seven
millimeters
(37mm) on each side and three hundred fifty millimeters (350mm) long. Other
dimensional specifications for a steam cooking capable packaging device may be
employed as contemplated by those of ordinary skill in the art. The second
base film
110 may be constructed in the configuration of a "strip" of material. The
strip may
have certain dimensional characteristics which allow it to be connected with
the first
base film in such a manner that it provides an integral overall appearance.
For
instance, the strip may be one-quarter inch (1/4") wide and have a length
which
corresponds to the length of the first base film 105. It is to be understood
that the
dimensional characteristics of the strip may vary without departing from the
scope
and spirit of the present invention. For instance, the strip may include a pre-
determined length that is shorter than the length of the first base film 105
and may
have a width less than or greater than one-quarter inch wide.
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To provide the packaging device with proper cooking properties a venting
system is
included. Thus, before the two base films are bonded together the first base
film 105
is provided a slit 115 (opening) on a continuous basis in a position that
corresponds to
the position of the bonding of the first base film 105 with the second base
film 110.
In a preferred embodiment, the bonding of the second base film 110 to the
first base
film 105 occurs using a lamination process where a lacquer is applied for
sealing the
first and second base films. Other sealing agents as contemplated by one of
ordinary
skill in the art may also be utilized. Thus, the slit 115 along a side of the
first base
film 105 is sealed by the lamination of the second base film 110 over the
opening. It
is contemplated that the web may be sealed either to itself or another
substrate, with
the seal formed being integral. On cooking, the pressure inside the package
increases
to a point where the seal in the area of the lacquer coating starts to break
open. The
bond provided by the seal has been engineered to break open (release) at a
particular
level of pressure build-up.
The breaking/opening of the lacquer seal over the slit 115 provides an outlet
through
which steam may escape. The seal may provide an outlet in various forms, such
as a
directed channel (communicating passage) which may direct the flow of the
escaping
steam to a single venting point or a series of apertures which may allow the
steam to
vent from and through multiple points of the seal. The single venting point is
an
opening located between the first base film 105 and second base film 110 which
allows the steam escaping through the slit 115 to exhaust into the outer
environment
outside the bag. In a multiple venting point configuration the second base
film 110
may include multiple openings through the film that upon a breakdown of the
lacquer
seal provide multiple channels through which steam may exhaust from the
interior
atmosphere of the bag to the outside environment. Alternative venting means as
contemplated by those of ordinary skill in the art may be employed without
departing
from the scope and spirit of the present invention and allow for the steam
cooking of
the packaged contents.
It is contemplated that the width and length of the slit 115 in the first base
film 105
may vary. For instance, the slit 115 may run the entire length of the bag or
may
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extend only a partial distance along the side of the bag. The slit 115 may
extend from
a starting point which is disposed proximal to or at an edge of the bag or the
slit may
be positioned in a generally central portion of the side of the bag.
Additionally, the
slit 115 may have a width ranging from one millimeter (lmm) to one half inch
(%z").
5 It is contemplated that various other slit widths as contemplated by those
skilled in the
art may be constructed within the side of the bag. Further, the dimensional
characteristics of the "strip" 110 used in sealing over the slit may vary to
accommodate the varying dimensional characteristics of the slit 115. For
example,
the "strip" 110 may have a length generally shorter than the length of the
bag. It is
10 further contemplated that the bag may be given multiple slits, which may be
sealed by
multiple "strips" and/or sealed to itself using the lamination process. In the
alternative, various sealing techniques may be employed, such as using various
adhesive or epoxy compounds to affect the seal. Further, the steam cooking
properties of the bag may arise from the use of structural variance within the
base
15 film. For instance, a specific section of the bag may be "thinned" or
otherwise
structurally degraded, such that upon cooking and the build up of pressure
within the
web of the packaging device the base film is caused to rupture at this
specific section.
This laminated strip configuration allows the packaging device to be used
during
steam cooking (such as cooking in a microwave oven) without significantly
altering
the steam cooking properties of the web. The steam cooking properties may
include
various structural integrity characteristics of the base film(s) material,
such as heat
resistance, moisture resistance, interior heat build-up and the like. Further,
the
lacquer seal used may be engineered with various structural characteristics
which
allow it to resist premature or delayed structural breakdown during the
cooking
process, thereby ensuring that the steam is allowed to escape and be vented at
the
proper time.
The packaging device 100 further includes a plurality of micro-perforations
120 for
breath-ability and quality protection of respiring and gas sensitive (one or
combination of 02, C02, C2H2 and H20 vapor) food products which are being
stored
within the interior atmosphere of the web. In a preferred embodiment,
described
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below in Example 2, the bags include nine (9) micro-perforations having a
diameter
of one hundred twenty microns (120 ) each. As will be described, the number
and
size of the micro-perforations may vary to accommodate the use of the
packaging
device with various food products. It is to be understood that the micro-
perforations
allow the packaging device to retain its steam cooking properties.
The micro-perforation technology employed is based upon the inventor's
discovery
that first, the tolerance to COa by the tissue of various perishable food
products may
be improved by increasing internal 02, and more particularly by maintaining
the
preferred ratios of COa to 02 in particular ranges, such as 2.5:1 to 3.5:1.
Thus, the
micro-perforation technology allows for the use of high CO2 and improved
levels of
02 for distribution and storability of fruits and vegetables. Second, that
within pre-
defined limits of COa and 02, that may be determined based on the food product
or
desired bag characteristics, water vapor (RH > 70%) and ethylene (>100ppm) may
interact in a synergistic fashion to confer addition quality protection and
shelf-life.
Thus, the micro-perforation technology (i.e., proper selection of base sheet,
hole size,
hole shape, hole number and hole positioning) employed for the various food
products
identified herein, is commensurate in scope with that disclosed in U.S. Patent
Serial
No. 10/855,305, which is herein incorporated by reference in its entirety.
Further, the
micro-perforations may allow the transmission of various agents through them,
such
as ripening agents, preserving agents, and the like.
The capabilities of the packaging device 100 to assist in optimizing the
quality and
shelf-life of the food products and allow for the cooking of the food products
in situ,
such as steam cooking in a microwave, is based upon: (i) micro-perforations
allow the
microwavable polymeric packaging device(s) to retain their steam cooking
attributes
(ii) micro-perforations may be employed to achieve a food product specific
internal
package (web) atmosphere of 02, COa and Water Vapor that confer quality
protection
and shelf-life extension during distribution and marketing, and (iii) methods
of
cooking fresh produce may be combined with the functions of breath-ability
provided
by the micro-perforated packaging. These capabilities are also present in the
various
embodiments shown in FIGS. 3 through 6 below.
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The application of the micro-perforation technology to a web of a packaging
device
(MAP system) with the cooking properties/capabilities described herein,
including the
proper selection of a base film, micro-perforation hole size, micro-
perforation hole
number and micro-perforation hole positioning may be conveniently and reliably
used
to achieve target atmospheres of 02, C02, and water vapor within the interior
atmosphere of the web. Further, the application of micro-perforation
technology to
various packaging devices that may be constructed in various sizes or shapes,
using
various materials and construction technologies and may employ various
modified or
controlled atmosphere technologies is contemplated by the present invention.
The size and number of the micro-perforations are determined based on the per
unit
weight (perishable (fresh) food product) to surface area (base film) ratio,
the
respiration rate of the fresh food products and the shelf life requirements.
It is
contemplated that the number and size of the micro-perforations for an
embodiment
of the packaging device may vary. Thus, it is contemplated that the present
invention
may be used to provide a determined shelf-life which may be a maximization of
the
shelf-life of the fresh food product or less than the maximum. Diameter of the
micro-
perforations may be in the range of one micron (1 ) to five hundred (500g)
microns,
more preferably from fifty microns (50g) to one hundred fifty (150g) microns.
The
number of micro-perforations included may range from one (1) to one thousand
(1,000), more preferably two (2) to one hundred fifty (150). The density of
holes
(micro-perforations) in the film will be determined by the above mentioned
parameters but will generally be in the range of five (5) to fifty (50) holes
per unit
weight (i.e., gram(s), ounce(s), pound(s), and the like) of fresh food product
offering
depending on the required open area and the base sheet gas transmission
properties.
The open area refers to the cumulative amount of open space through the base
film(s)
of the packaging device provided by the micro-perforations. For example, a
film
having two micro-perforations would have its total open area defined by the
cumulative size (area) of each the openings. Thus, if each of the openings of
the two
micro-perforations have a diameter of twenty microns (20g) ( = 10'6m) then
the
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surface area (open area of the micro-perforation) of each micro-perforation
will equal
7r multiplied by (10x10-6m)2 or surface area = 711', this amounts to 3.14x10-
10m of
open area. Therefore, the open area provided by the two micro-perforations may
be
substantially equal to 6.28x10-10m. It is to be understood that the required
open area
may be pre-determined based upon the type of perishable food product to be
stored
within the packaging device of the present invention or based on various
alternatives,
such as a pre-determined number of micro-perforations, pre-determined
respiration
rate, and the like without departing from the scope and spirit of the present
invention.
lo Since percentage of open area is important, there is an interaction between
hole size
and hole density. The base film, hole size and hole number are selected to
achieve
oxygen (02) levels in the range of two percent (2%) to eighteen percent (18%)
and
more preferably less than ten percent (10%), carbon dioxide (C02) levels in
the range
of five percent (5%) to twenty-two percent (22%) and a relative humidity (RH)
equal
to or greater than seventy percent (70%), more preferably ninety percent (90%)
to
ninety-nine percent (99%). The packaging device may further maintain an
interior
atmosphere with a preferred ratio of CO2 to 02. The ratio of COa to 02 may
vary
depending on various factors, such as the respiration rate of the food
product. As
stated previously, the ratio may range from 2.5:1 to 3.5:1 or have a higher or
lower
ratio factor as determined by the respiration needs of the food product or
desired
design characteristics of the bag. Therefore, the ratio may vary and the
interior
atmosphere may have a higher or lower CO2 and/or 02 concentration without
departing from the scope and spirit of the present invention.
Referring now to FIGS. 3 and 4, a packaging device is constructed as a lid
stock 200
including a first base film 205. In a preferred embodiment, the first base
film 205 is a
transparent polypropylene for connection with a tray 215. The lid stock 200
further
includes a plurality of micro-perforations 210 that extend through the first
base film
205 and provide the advantages of the present invention for the storage,
distribution
and cooking of a perishable food product. In the current embodiment, the lid
stock
200 is generally configured as a transparent film which connects with and
seals the
tray creating a closed interior atmosphere. It is to be understood that the
lid stock 200
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may be constructed from any of the various materials identified previously and
include various structural properties, such as being transparent, translucent,
opaque,
and the like, and having various rigidity characteristics. The lid stock 200
is capable
of being constructed to provide proper sealing of variously configured trays
and the
like. Thus, the lid stock 210 may be constructed in a pre-determined pattern
to
successfully engage with a specific tray having certain dimensions. In FIG. 5,
the
packaging device is shown alternatively constructed as a roll stock 300
including a
base fihn 305. It is contemplated that the roll stock 300 may be any of the
numerous
plastic wraps currently available that are modified to include the micro-
perforations
and provide the user the ability to determine overall roll stock 300 length
for
engagement with various trays. The roll stock 300 also includes a plurality of
micro-
perforations 310 which allow it to provide a proper internal atmosphere when
the roll
stock 300 is sealed with a tray 315. It is contemplated that the lid stock 200
and/or
roll stock 300 may be variously configured, such as in various polygonal
configurations like a generally square shape, rectangular shape, diamond
shape, and
the like, or other configurations, such as an conical shape, oval shape, and
the like, for
connection with a tray in establishing a modified atmosphere system.
The lid stock 200 and/or roll stock 300 may be used during a cooking process,
allowing a food product stored between the tray and the lid/roll stock to be
cooked.
The micro-perforations included allow the lid/roll stock to retain its cooking
properties. The number and size of the micro-perforations may vary in
accordance
with that indicated previously. Preferably, the number of micro-perforations
may
range from two (2) to seventy-eight (78) and have a diameter ranging from one
micron (1 g) to one hundred fifty microns (150g).
A stand-up pouch 400 including a first base fihn 410 connected with a second
base
film 415, wherein the first base fihn 410 includes a plurality of micro-
perforations
420 is shown in FIG. 6. The stand-up pouch 400 is capable of steam cooking its
packaged contents and may be variously configured including dimensional
characteristics, such as a width of the pouch ranging from one hundred sixty
millimeters (160mm) to one hundred ninety-five millimeters (195mm) and the
length
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of the pouch ranging from one hundred eighty millimeters (180mm) to one
hundred
ninety-five millimeters (195mm). The length and width of the stand-up pouch
may be
greater than or less than the ranges identified above without departing from
the scope
and spirit of the present invention.
5
It is contemplated that the configuration of the stand-up pouch 400 may be
determined by the amount or weight of food product to be stored. The stand-up
pouch
400 may be constructed to hold various food product weights ranging from one
hundred eight grams (180g) to four hundred fifty grams (450g). Food product
10 weights which are greater than or less than the range provided may be
accommodated
by the present invention. The dimensional and volumetric approaches to
configuring
the stand-up pouch 400 allows for the construction of pouches specific to a
consumer
need.
15 The number (density) and size (diameter) of the micro-perforations 420
included in
stand-up pouch 400 may vary as well. Generally, the number of micro-
perforations
per bag is in accordance with that previously mentioned, preferably the number
of
micro-perforations range from two (2) to twenty-four (24). In the current
embodiment, twenty (20) micro-perforations are included to extend through the
first
20 base film 410 and allow the transmission of gases between the stand-up
pouch 400
interior space and an external environment. The micro-perforations are
generally
sized in accordance with that previously mentioned, preferably the micro-
perforations
have a diameter of one hundred twenty microns (120 ). It is contemplated that
the
number and size of the micro-perforations per stand-up pouch may vary without
departing from the scope and spirit of the present invention.
The stand-up pouch of FIG. 6 includes a venting system 430 that allows for the
release of pressure build-up during a cooking process. In a preferred
embodiment, the
venting system includes an area of the first base film 410 (CPP film) which is
coated,
in register, with a laquer. The lacquer seal bonds the first base film 410
with the
second base film 415 and starts to break open upon an increase of pressure
within the
interior of the stand-up pouch during the cooking process. In the current
embodiment,
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the area on the first base film 410 of the stand-up pouch 400 is punch slit,
folded back
on itself and heat sealed to form an external flap on the back of the pouch,
wherein the
punch slit penetrates fifty percent (50%). A seal is formed about four
millimeters in
width, in the center aligning the seal with the punch slit. The seal may be
arrow
shaped or may be variously configured to allow for the operation of the
lacquer seal in
releasing the build-up of pressure during cooking. Because this central arrow
shaped
sealed area has been pre-coated with the laquer the heat seal at this point is
weakest.
In this embodiment, due to the arrow shaped configuration of the laquer
application,
the loosening of the seal due to pressure buildup leads to the formation of a
hole
1o allowing pressure buildup (i.e., stearn) to escape.
The lid/roll stock and stand-up pouch of FIGS. 3 through 6 also include micro-
perforations to assist in increasing the shelf-life and quality of the food
products
contained within. As with the bag of FIGS. 1 and 2, the micro-perforations
continue
to allow the lid stock and stand-up pouch to substantially retain the steam
cooking
properties as these items had without the presence of the micro-perforations.
Thus,
the micro-perforation technology may be utilized with exiting storage (bag,
lid/roll
stock, pouch) technologies or in conjunction with newly constructed storage
technologies. As described below in reference to Examples 4 and 5, the number
and
size of the micro-perforations for the lid/roll stock and stand-up pouch may
vary to
accommodate various factors.
The micro-perforated packaging device(s) which have been described and are for
use
with perishable food products (fresh produce), such as broccoli florets,
cauliflower,
carrots, corn, and the like, which exhibit a higher rate of respiration over
that of
alternative food products, provide an advantage over the use of conventional
solid
(i.e., no holes) film packaging or other packaging devices which attempt to
provide
modified atmosphere capabilities, both of which may over-modify the atmosphere
within the packaging resulting in fermentation. The non-perforated (solid)
film
packaging devices currently employed, due to the over modification of the
atmosphere within the packaging,'reduce the shelf-life of the food product as
will be
further described in detail below.
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Additionally, moisture control is considered equally essential in preserving
the quality
of fresh food products, such as the broccoli florets, carrots, corn, and the
like, and
assisting in providing prolonged shelf-lives for these products. A micro-
perforated
packaging device furtlier assists in ensuring the proper moisture content
within a
packaging containing fresh food product(s). As stated previously, the micro-
perforated packaging devices allow an internal atmosphere to maintain a
desired
relative humidity (i.e., 70-99% RH). Thus, the micro-perforated packaging
devices
maintain a moisture level within the packaging devices, such that condensate
is
continually maintained within the interior atmosphere of the packaging device.
This
maintenance of condensate assists in promoting the quality and extended shelf-
life
characteristics provided by the packaging device(s) including micro-
perforations of
the present invention.
The micro-perforated film of the web containing the fresh perishable food
products
includes a micro-perforation hole size and density which allows a proper
internal
atmosphere for the fresh food products (florets) to be achieved. This assists
in
preventing fermentation of the fresh food product within the packaging,
maintaining
sufficient moisture for the achievement of optimum quality and extended shelf
life of
the fresh food product.
The following examples provide a comparison of the micro-perforation packaging
devices of the present invention and conventional (non-perforated) packaging
devices.
Comparison of performance characteristics of the packaging devices and the
food
products contained within are detailed for the areas of steam cooking, quality
and
shelf-life.
While broccoli, carrots, cauliflower and corn have been used as test models
for this
invention, the teachings of this invention may easily be extended to other
food
product offerings that have perishable/fresh food products, such as fresh
produce
and/or meats, in their ingredient mixes. For instance, the present invention
may be
used to provide a Ready-to-Eat meal. A Ready-to-Eat meal may be comprised of
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various food products contained within a single/individual packaging device.
For
example, one Ready-to-Eat meal may comprise a mixture of different produce
food
products. Alternatively, a Ready-to-Eat meal may comprise a meat food product.
Further, a Ready-to-Eat meal may include a mix of at least one produce food
product
and at least one meat food product. It is contemplated that various spices,
herbs,
seasonings, dressings, flavoring substances, and the like may be included in a
Ready-
to-Eat meal contained within a packaging device of the present invention. The
packaging device may advantageously provide the Ready-to-Eat meal with the
steam
cooking performance characteristics and improved shelf-life performance
characteristics shown in the examples provided below and previously discussed,
herein.
Example 1
Exam.ple 1, demonstrates the effects of two (2) minute steam cooking on the
internal
package pressure, internal package temperature, product temperature and
organoleptic
product quality of various fresh produce products using non-perforated CPP-PE
laminate bags (121 mm wide with additional gusset width of approximately 37 mm
on
each side and 350 mm long).
Gusseted bags made from CPP-PE laminate were used to pack shredded carrots,
broccoli, cauliflower and corn. Eight ounces of product were packed in these
bags
individually, heat sealed and steam-cooked for 2 minutes using an 800 watt
microwave oven. Pressure buildup within the bags during cooking, internal bag
temperature, product temperature and organoleptic properties were recorded.
Further,
organoleptic analysis based on taste, flavor retention and appearance was
performed
using a rating scale of 1 to 5, 5 being excellent, 4 being very good, 3 being
good, 2
being poor and 1 being unacceptable.
Table 1. Conventional Packaging device -- Effect of steam-cooking on pressure
3o,, buildup, bag temperature, product temperature and organoleptic rating
score of
various fresh produce food products.
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Product Name Pressure (m Internal Bag Product Temp Organoleptic
bars) Temp ( C) ( C) Score
Shredded
Carrots 93.2 94.5 4.2
Cauliflower 95.1 97.2 4.5
Broccoli 92.3 97.1 4.7
Corn 96.6 100.4 5.0
Example 2
In Example 2, a packaging device of the present invention was used to
demonstrates
the effects of micro-perforations on steam cooking properties of CPP-PE
laminate
bags for various fresh produce products (bag dimensions and fresh produce
products
used were identical to those in Example 1).
These CPP-PE laminate gusseted bags, each bag having nine (9) micro-
perforations of
one hundred twenty microns (120 ) in diameter, were used to pack shredded
carrots,
1o broccoli, cauliflower and corn. Eight ounces of the fresh produce food
product were
packed individually in the bags, heat sealed and steam-cooked for 2 minutes
using an
800 watt microwave oven. Pressure buildup within the bags during cooking,
internal
bag temperature, product temperature and organoleptic properties were recorded
in a
manner similar to that used and described in Example 1.
Table 2. MAP System -- Effect of steam-cooking on pressure buildup, bag
temperature, product temperature and organoleptic rating score of various
products.
Product Name Pressure (m Internal Bag Product Temp Organoleptic
bars) Temp ( C) ( C) Score
Shredded
Carrots 94.8 96.4 4.5
Cauliflower 96.6 98.3 4.3
Broccoli 96.5 98.8 5.0
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Corn 98.2 100.5 5.0
A comparison of the data from Table 1 and Table 2 demonstrates that the steam
cooking properties exhibited by the two different bags were substantially
similar.
Therefore, the steam cooking properties of the packaging devices (bags
including
5 micro-perforations) were substantially equivalent and for some properties
showed
increased performance characteristics over the conventional non-perforated
packaging
devices. Thus, the packaging devices may be developed as product specific
micro-
perforated packages for shelf life extension while retaining the steam cooking
properties of the packages.
Example 3
Example 3 compares the shelf life of broccoli florets that were packed in non-
perforated and micro-perforated CPP-PE laminate bags in units of one pound (1
lb)
product and held at 5 C. The bag size for micro-perforated and non-perforated
packages was nine by twelve (9 x 12) inches. The micro-perforated bags
included
sixteen (16) micro-perforations of one hundred twenty microns (120 ) in
diameter.
On day three of the evaluation, the non-perforated bags were fully bulged. The
bags
were completely anaerobic as the package oxygen (02) was around 0.5% and
carbon
dioxide (CO2) content was 30%. On bag opening, strong off-flavor notes were
detected indicating the occurrence of fermentation of the broccoli florets
within the
non-perforated bags. By contrast, the broccoli florets in micro-perforated
packages
were in excellent condition. The internal atmospheres of micro-perforated bags
was
measured to consist of 12% oxygen (02) and 10% carbon dioxide (C02) on day
three
of holding. No off-flavor notes were detected in the perforated packs
indicating the
non-occurrence of fermentation of the broccoli florets. While the shelf life
of broccoli
florets stored in the non-perforated packs was less than three (3) days, the
micro-
perforated packages allowed a storability of twenty-one (21) days at 5 C of
the
broccoli florets. This increase in storability (shelf-life) is provided by the
gas
transmission capabilities allowed by micro-perforations of the packaging
devices.
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Example 4
Example 4 illustrates the applicability of the invention to fresh produce tray
offerings.
A lid stock including micro-perforations was utilized to provide a packaging
device in
accordance with the present invention. Thus, three corn cobs weighing
approximately
510 grams were packed in a six by nine inch polypropylene tray lidded with
micro-
perforated CPP-PE laminate and held at 5 C. The micro-perforations were
positioned
such that eight (8) micro-perforations of one hundred twenty microns (120 g)
in
diameter size were included per impression.
Similar to Examples 1 and 2 above, the steam cooking properties of this
packaging
device were uninfluenced by the presence of the micro-perforations. In
addition, the
corn achieved a shelf-life of fourteen (14) days. By comparison, the corn
packed in
polypropylene trays lidded with non-perforated CPP-LE laminate became
anaerobic
(began fermenting) on day two (2) of packing. Thus, the packaging device of
the
present invention provides a significant shelf-life advantage over that which
may be
achieved using a conventional, non-perforated tray and lid which further
assists in the
storing, distributing, retailing, and cooking of such perishable food
products.
2o Example 5
Example 5 illustrates the applicability of the invention to fresh produce
pouch
offerings. Such pouch offerings provide a Ready-to-Eat food product to the
consumer.
A mixture of broccoli, cauliflower and carrots was packed in CPP-PE micro-
perforated pouch fitted with a pressure release valve and held at 5 C. It is
to be
understood that the pouch is generally a standard stand-up pouch, such pouches
being
currently employed on a large scale within the food product retailing
industry, that
includes micro-perforations. The micro-perforations were positioned such that
twenty (20) micro-perforations of one hundred twenty microns (120 ) in
diameter
size were included per impression.
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Using the micro-perforated pouch, the perishable food products within achieved
a
shelf life of twelve (12) days and the steam cooking properties were
uninfluenced by
the micro-perforations. By comparison, the product mixture consisting of
broccoli,
cauliflower and carrots packed in non-perforated CPP-LE laminate pouches
became
anaerobic (began fermenting) on day three (3) of packing. Again, the micro-
perforation of the pouch in order to provide a packaging device in accordance
with the
present invention assists in the storing, distributing, retailing, and cooking
of such
perishable food products as compared to conventional packaging devices.
The shelf-life capabilities of such perishable food products within the
packaging
devices including the micro-perforation technology is significant when
compared to
the shelf-life achieved by the non-perforated, conventional packaging devices.
In
Example 3, the shelf life was extended from three (3) days (non-perforated
pouch) to
twenty-one (21) days (micro-perforated pouch) and in Exaxnple 4, the shelf
life was
extended from two (2) days (non-perforated) to fourteen (14) days (micro-
perforated).
Both of these examples indicate that the perforation of the pouch and lidstock
exhibit
an increase in the shelf life of the perishable food product stored within of
700%. The
mixture of food products in Example 5 showed that the non perforated container
provided the food products a shelf life of only three (3) days while the micro-
perforated container provided the food products a shelf life of twelve (12)
days, an
increase in the shelf life of the food products of 400%.
As previously mentioned, the micro-perforation technology may be employed to
provide various gas transmission properties across the boundary of the base f
lm used
for constructing the web of the packaging device. For instance, the size and
density
of the micro-perforations may be determined to provide a food product
contained
within a packaging device of the present invention with an increase of shelf
life of
anywhere from 25% to 700% based off of the shelf life provided by a non
perforated,
conventional packaging device. Thus, where a conventional packaging device may
provide four (4) days of shelf life before fennentation begins, the 1VIAP
system may
provide a shelf life of five (5) to twenty-eight (28) days. It is also
contemplated that
the micro-perforation technology may be employed to provide a desired shelf-
life of a
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food product which is less than or greater than the shelf-life ranges
identified above.
For example, the micro-perforation technology may be employed to provide a
four (4)
day shelf-life or greater than twenty-nine (29) day shelf-life.
The micro-perforation technology for constructing a packaging device in
accordance
with the present invention may be employed with various types of packaging
devices,
such as over-the-counter products. For instance, a conventional packaging
device,
such as the bag described above in the examples, may be micro-perforated to
provide
a packaging device of the present invention. Various self-adhering plastic
based film
products, such as the roll stock shown in FIG. 6, may be micro-perforated to
provide a
packaging device in accordance with the present invention. These conventional,
over-
the-counter products, including such devices as the stand-up pouch, may have
micro-
perforations included in a post production process. These various packaging
devices
may provide steam and other cooking capabilities in order to facilitate the
increased
ease of use of the food products contained within.
Referring now to FIG. 7, a method 500 of cooking a perishable food= product is
provided. In a first step 505 a perishable food product is selected. The
perishable
food product may be one food product or a combination of food products. The
perishable food product may further be selected from produce or meat food
products
without departing from the scope and spirit of the present invention. After
the
selection of the perishable food product, a packaging device including micro-
perforations is selected in step 510. The packaging device may be in
accordance with
any of the exemplary embodiments shown in previous drawing figures and
describe
above. The packaging device may be selected on the type of perishable food
product(s) and their respiration rate or the weight of the food products may
determine
the packaging device selected. The selection of the packaging device may be
further
determined by the number of micro-perforations included on the packaging
device.
For instance, a first bag may have a certain number and size of micro-
perforations and
it may be known that that number of micro-perforations at that size do or do
not allow
for the packaging device to provide a proper internal atmosphere for the type
and
weight of perishable food product selected. Therefore, that particular
packaging
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device may or may not be selected. It is contemplated that the packaging
device
selected may not provide the maximum shelf-life characteristics as described
above in
the examples for a particular perishable food product. It may be the case that
other
considerations such as strength or rigidity of material may be a more
important
consideration. Other considerations as contemplated by those of ordinary skill
in the
art may be factored into the selection of the packaging device in the current
method.
Once the packaging device is selected, in step 515 the selected perishable
food
product(s) is placed within and the packaging device is sealed about the
perishable
food product(s). As described previously, the sealing of the packaging device
may be
through use of an integral seal, such as a heat sealing technique, or a re-
sealable
technology. It is to be understood the at the packaging device may allow for
expansion in its interior space in order to accommodate the storing and
sealing about
of the perishable food product within the interior space. The expansion
capabilities
may be provided through various systems, such as the stand-up pouch system and
or
gusset system described previously. Other systems as contemplated by those of
skill
in the art may be employed without departing from the scope and spirit of the
present
invention.
With the perishable food product sealed within the packaging device, the
packaging
device is then placed in a cooking apparatus (i.e., microwave oven, convection
oven,
open flame grill, or the like) and cooked in step 520. The cooking apparatus
is heated
and transfers that heat to the packaging device, which in turn transfers that
heat to the
perishable food product stored within. It is a particular advantage of the
micro-
perforations included within the packaging device that they do not affect the
cooking
properties of the packaging device as the perishable food products are being
cooked.
The cooking time, as determined by the operator of the cooking apparatus,
identifies
the completion the cooking process for the perishable food product. Thus, the
packaging device of the instant invention allows for the cooking of a
perishable food
product.
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It is further contemplated that the packaging device employed for this method
of
cooking a perishable food product includes a venting system which allows
pressure
that builds up within the interior space of the packaging device during the
cooking
process, to escape. The venting system employed for this method of cooking the
5 perishable food product may be similar to those describe previously for the
exemplary
embodiments of the present invention. In another step of the current method,
after the
cooking process is completed the user may remove the packaging device and
cooked
perishable food product from the cooking apparatus and unseal or open the
packaging
device and remove the cooked perishable food product. After removing the
10 perishable food product it is contemplated that the user may then eat the
cooked
perishable food product.
Referring now to FIG. 8 a method 600 of prolonging the shelf-life of a
perishable
food product is shown. In a first step 605 a perishable food product is
selected. The
15 perishable food product may be fresh produce, such as fruit(s) and/or
vegetables.
After selecting the food product a packaging device including micro-
perforations is
selected in step 610. The packaging device may be selected based on the
ability of
the micro-perforations to provide a desired interior atmosphere within which
the food
product will be stored. Additionally, the respiration rate, size, weight, and
dimensions
20 of the food product may be a factor in selecting a packaging device.
Further, the gas
transmission properties of the material used to construct the packaging device
may be
a factor in the selection of a packaging device. The desired internal
atmosphere, is one
that extends the shelf-life of the food product during the distribution and
storing of the
food product and promotes the maintenance of the quality of the food product.
It is
25 fu.rther contemplated that the packaging device may be selected based on
its cooking
properties which in combination with the micro-perforations allows the food
product
to be cooked while still in the packaging device. The method of cooking may
vary as
previously stated to include steam cooking, cooking over an open flame, and
the like.
After selecting the packaging device, in step 615, the perishable food product
is
30 placed within and the packaging device is sealed about the food product.
The seal
may provide an integral connection or a releasable connection.
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The method further contemplates the step of distributing the food product
contained
within the packaging device to a retail establishment. Once received by the
retail
establishment, the packaging device may then be placed on display. Display may
occur within various environments, such as refrigerated, non-refrigerated, and
the like
without departing from the scope and spirit of the present invention.
In FIG. 9, a method 700 of providing a Ready-to-Eat product is shown. The
Ready-
to-Eat product first includes the selection of a food product(s) in step 705.
The food
product(s) is then placed and sealed within a packaging device including micro-
perforations for storage in step 710. The Ready-to-Eat product may be
distributed
and/or displayed in a retail environment in order to facilitate its use by a
consumer. In
step 715 the Ready-to-Eat product is cooked using one of the various methods
identified, such as steam cooking, convection oven cooking, barbequing, and
the like.
After cooking the packaging device may then be opened and the food product
contents removed in step 720. Tn an additional step the user may consume the
cooked
food product removed from the packaging device including micro-perforations.
Thus,
the packaging device employed in a Ready-to-Eat product may provide a retailer
an
increased shelf-life which may increase sales and the consumer an increased
ease of
use and prolonged freshness of the perishable food products within.
In any of the methods of manufacturing a packaging device, as described above,
it is
contemplated that various identifiers, such as an insignia, label, logo, sign,
symbol,
icon, moniker and other identifying marks may be included on the packaging
device.
These various identifiers may be integrally formed upon the web during
manufacturing or may be connected to the web. Alternatively, connection of
various
identifiers may occur by adhesion through the use of glues, sealants, and the
like as
contemplated by those of ordinary skill in the art.
The packaging and method of the instant invention, pursuant to a preferred
embodiment thereof, are based upon the inventor's discovery that (i) tolerance
to COa
by banana tissue can be improved by increasing internal 02, and more
particularly by
maintaining the preferred ratios of CO2 to 02 in the range of 2.5:1 to 3.5:1,
which
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discovery evolves to the concept of using high CO2 and improved levels of 02
for
distribution and storability of fruits and vegetables; and (ii) within the
above
described limits of COa and 02 as defined above, water vapor (RH > 70%) and
ethylene (>100ppm) interact in a synergistic fashion to confer additional
quality
protection and shelf life.
In a preferred embodiment, micro-perforation technology (e.g. proper selection
of
base sheet, hole size, hole shape, hole number and hole positioning) can be
conveniently and reliably used to achieve target atmospheres of 02, C02, water
vapor
and ethylene. As stated previously, it is conceivable that the base film could
consist
of a number of polymer groups such as polyalkenes (e.g., polyethylene - low
and
ultra low density, linear low density, high density, etc.), polyvinyls (e.g.,
polypropylene, oriented polypropylene), polystyrenes (e.g., polyvinyl
chloride),
polysiloxanes (e.g., silicone rubber), polydiens (e.g., natural rubber), and
laminates of
the foregoing, as well as metallocene films and coextruded films, all with or
without
antifog agents. The base film can be extruded from a single polymer or blends
of
various polymers where each polymer performs a specific function, such as
contributing strength, transparency, sealability, or machineability, to meet
specific
product requirements. Similarly, films can be laminated to achieve specific
properties. Other methods of creating these environments during distribution
and
marketing may include the use of other modified atmosphere and/or controlled
atmosphere technologies.
In a particularly preferred embodiment of the invention, an inexpensive
polyethylene
bag is used for all or one of the purposes of packaging, transport, ripening,
distribution, marketing and yellow life extension of banana fruit. The bag may
be
custom tailored for individual bananas or packages of, for example, 1 to
401bs. The
fruit may be packaged in hands consisting of 4 to 10 bananas per hand or in
packages
consisting of individual fingers. For instance, this invention was
successfully tested
for standard 2.5 to 3.5 lb. bags having fruit in clusters for supermarket and
food
service distribution, and for 2.5 to 3.5 lb. bags consisting of 8 single
fingers/bag for
food service distribution. The bag for these two applications consisted of low
density
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polyethylene having a size of 17" x 12", thickness of 1 mil and 44
perforations of 100
size.
Using polymeric films of differing permeabilities, modified atmospheric
packaging
systems for products with low to medium respiration rates have been developed
with
varying degrees of success. One previously known technology has been film
packaging for leafy greens. However, banana fruit exhibit a much higher rate
of
respiration, such that conventional solid (i.e., no holes) film will over-
modify the
headspace atmosphere resulting in fermentation. Additionally, moisture control
is
1o considered equally essential to preserve the peel health and thereby the
appearance of
the banana fruit. To overcome these problems, it is best to design a
perforated film
with a combination of hole size and density that allows the fruit to achieve
the desired
atmosphere without fermentation and to maintain sufficient moisture for the
achievement of optimum quality and extended shelf life of the ripening fruit.
As
explained above, a polymeric fihn (e.g. LDPE, LLDPE, HDPE, OPP COPP, laminates
of different polymers) is selected as the base sheet, LDPE being preferred.
Size and
number of the perforations are determined based on the weight (bananas) to
surface
area (film) ratio, the respiration rate of the bananas, and the shelf life
requirements.
Diameter of the perforations can be in the range of five microns (5 ) to five
hundred
microns(500 ), and preferably have a mean diameter of one hundred microns
(100 )
to one hundred thirty microns (130 ). The density of holes in the film will
be
determined by the above mentioned parameters but will generally be in the
range of
eleven (11) to one hundred (100) holes per pound of bananas depending on the
required open area and the base sheet gas transmission properties. Since
percentage
of open area is important, there is an interaction between hole size and hole
density.
In general, better and more uniform results are achieved with small holes and
higher
nuniber of holes. The base sheet, hole size and hole number are selected to
achieve
package atmospheres during the later portion of storage that comprise 02
levels in the
range of <10%, COa levels in the range of 5 - 20%, and RH of >70%.
Microperforations may be made using a number of methods known to those skilled
in
the art, including but not limited to laser perforation.
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With regard to another aspect of the invention, a preferred embodiment
utilizing the
packaging method of the instant invention consists of the following steps:
(1) Enclosing the green fruit at color stage 1 to 2 in micro-perforated bags
in their country of origin, the atmospheric composition within the bag being
approximately ambient atmosphere.
(2) Packaging the enclosed fruit in standard corrugated containers and
packing the corrugated containers in refrigerated sea containers for shipment
to their
destination. Depending on the destination, transportation times can vary from
5 days
to more than 21 days. During transit and arrival at the destination, the
atmospheric
lo composition within the sealed bags is preferably maintained at >10% 02 and
<10%
C02.
(3) Ripening the bananas with exogenous application of >100 ppm
ethylene at 56 to 64 F through standard corrugated box and inner sealed bag
to the
preferred distribution color stage of 3.0 to 3.5. At this preferred
distribution color
stage, the atmospheric composition within the sealed bags is preferably
maintained at
>5% 02 and <12% CO2.
(4) Distributing the bananas to retail and food service outlets post color
stage 3.5. The atmospheric composition of the bag during supermarket or food
service display is preferably maintained at >2% 02 and >5% C02, and more
preferably >10% CO2. Alternatively, the bags can be opened and fruit sold as
loose
fruit at the supermarket level.
Notably, the invention set forth herein is likewise useful for applications
which utilize
"active packaging," i.e., where the fruit is initially sealed in the package
in an
environment having predetermined levels of 02, C02, and N2.
Thus, the bananas are packed in bags according to the first aspect of the
invention at
air atmospheres in the producing country, transported to the port of
destination and
ripened to the desired supermarket color stage of 3.5 to 4 via conventional
exposure to
ethylene through the bag. The respiration rate of the banana fruit is slow in
green and
earlier states of ripening (color stage <3.5), and it increases approximately
5-fold post
color stage 3.5. The increased demand for respiratory 02 post color stage 3.5,
coupled
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with the appropriate design of microperforations (hole size and density,
positioning,
etc.) makes the package and method of packaging set forth herein particularly
useful
for bananas. The slow rate of respiration in green and earlier stages of
ripening helps
to keep the 02 high enough (>5%) and COa low enough (<12%) such that no
5 appreciable delay to color stage 3.5 occurs. Once the respiration rate post
color stage
3.5 starts increasing rapidly, the package 02 declines and COZ increases such
that
fu.rther progression of ripening is delayed and shelf life extended for
commercial
needs. Using such package and method of packaging in accordance with the
instant
invention, the yellow life of the banana fruit so packaged is extended in the
desired
lo eating range, preferably to 5-6 days.
EXAMPLES
Example 6
In Example 6, the effect of various combinations of package 02 and CO2 on peel
15 blackening and storability of the banana fruit was studied. Bags 12 inches
wide and
17.7 inches long were made from microperforated monolayer styrene butadiene
(XC)
film. Perforations were sized at 120 in diameter (for Treatments 1 through 3
in
Table 3) and 1000 in diameter (for Treatment 4). The number of holes per
unit of
film area (424.8 square inches) for 3 pounds of bananas was adjusted as
follows:
20 1. 10 holes of 120 size/bag
2. 30 holes of 120 size/bag
3. 42 holes of 120 size/bag
4. 30 holes of 1000 size/bag
Fruit at color stage 4 was heat sealed into these bags and further progression
of fruit
25 ripening and senescence was studied for a 7 day holding period at 20 C.
From this
study, one will note that with 02 levels achieved in treatments 2 and 3 (4.3%
and
5.7%) in combination with 14.5 to 15% COZ, an increase of 3 days in shelf life
extension was achieved (Table 3, comparing Treatments 2 and 3 with Treatment
4).
In contrast, in Treatment 1, where the internal package 02 was 2.2% and CO2
was
30 19%, an extension in shelf life of 1 day was achieved (Table 3, comparing
Treatment
1 with Treatment 4). The termination of shelf life in this treatment was due
to peel
blackening on day 4 of holding. When the fruit was packed in bags of Treatment
1
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and CO2 levels were maintained at approximately 0.5% by using CO2 absorbing
material, peel blackening was completely eliminated. This suggested that peel
blackening in banana is induced by accumulation of high C02 in the package
atmosphere. Surprisingly, peel blackening of banana fruit can also be avoided
if the
package 02 and COz atmospheres are in the ratio of 2.5 to 3.5 (Table 3,
Treatments 2
and 3). This leads to extension in shelf life by 3 additional days (Table 3,
comparing
Treatments 2 and 3 with Treatment 4).
TABLE 3: Effect of internal package 02 and COa achieved by package perforation
on
shelf life, visual quality (peel blackening and sugar spots) and internal
quality
(firmness, brix, taste, and flavor) of banana fruit packaged at color stage 4.
Treatment Oz C02 Shelf 2Visual 2Internal
(%) (%) life
(days)
1 90% yellow with Very Soft texture,
10 holes of 2.2 19.0 4 green tips, Severe Firmness of 0.85 Lbs,
120 size Peel Blackening Brix reading of 18, Pulp
(PB) on all fruits, appeared 1 color stage
Very few sugar spots more advanced in
(SS) but fruits ripeness than Peel. Fruits
unacceptable due to had ethyl acetate note in
PB on day 4 of taste.
holding.
2 100% yellow, No Firm texture, Firmness of
30 holes of 4.3 15.0 6 Peel Blackening, 1.20 Lbs, Brix reading of
120 size 50% fruits had SS. 21, Pulp appeared 0.5
The SS very small in color stage more
size. Fruits advanced in ripeness than
acceptable on day 6. Peel. Fruits had normal
banana flavor.
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3 100% yellow, No Firm texture, Firmness of
42 holes of 5.7 14.5 6 Peel Blackening, 1.15 Lbs, Brix reading of
120 . size 70% fruits had SS. 21.1, Pulp appeared 0.5
The SS very small in color stage more
size. Fruits advanced in ripeness than
acceptable on day 6. Peel. Fruits had normal
taste.
4 100% yellow, No Moderate texture,
30 holes of 18.5 3.5 3 PB. SS observed on Firmness of 0.95 Lbs,
1000 size day 3 on 90% fruits. Brix reading of 21, Pulp
Fruits unacceptable appeared 0.5 color stage
on day 3 due to large more advanced in
size and frequency of ripeness than Peel. Fruits
SS. had normal banana taste.
1Package 02/CO2 data is at day 4 of holding.
2The subjective analysis for internal quality was performed at the termination
of shelf
life. Termination of Shelf Life was determined either by visual appearance of
sugar
spots (Treatments 2,3 and 4) or visual appearance of peel blackening
(Treatment 1).
Example 7
In Example 7, the effect of a microperforated LDPE bag on ripening to color
stage 3.5
at 56 F in a standard ripening room and subsequent color progression at 68 F
(Figures 1 and 2) was evaluated.
As shown in Figure 10, a ripening scale of 1 to 7 (where 1 is complete green,
7 is full
yellow with onset of sugar spots, and the remaining stages represent increase
in
yellowness with increase in color stage) was used for evaluating the color
progression
of fruits. Notably, 90% of the fruits packaged in a microperforated bag in
accordance
with the invention herein reached color stage 3-3.5 on day 4 of ripening. This
evidences the fact the package and method of the instant invention does not
lead to
any commercially measurable delay to supermarket-preferred color stages.
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Likewise, as shown in Figure 11, use of the package and method according to
the
invention leads to highly uniform color, as evidenced by the fact that all
fruit
packaged according to the invention exhibited color stage 5 at day 4. In
contrast, the
fruits in the control bags had fruit at a broad range of color stages (color
stage 4.5p
through 5p). Notably, the control fn.iits developed sugar spots in earlier
stages of
ripening denoted by 4.5p and 5p. Normally, the color progresses to color stage
6.5
and at that point sugar spots develop. The package and method of the instant
invention lead to normal color progression, and delay in onset of sugar spots
until at
least color stage 7.
Example 8.
In example 8, the effect of macro-perforated LDPE bag and micro-perforated
LDPE
bag packaging on the ripening and storability of green bananas was determined.
Green banana fruits were packaged in commercially used macroperforated LDPE
bags and in microperforated LDPE bags according to the invention, stored for 2
weeks at 58 F to simulate actual transit conditions, and ripened with
ethylene for an
additional 4 days at 62 F. At color stage 3.5, the fruits were pulled out of
storage and
held at 68 F for subsequent color progression, shelf life, and quality
evaluations.
Upon inspection, it was confirmed that LDPE bags according to the invention
did not
delay the ripening process to color stage 3.5, provided highly uniform
ripening,
extended the yellow life of the bananas, did not interfere with the usual
taste and
flavor quality of the bananas, caused the fruit to maintain higher firmness
during
storage post color stage 3.5, and led to 3 days of extension in shelf life of
the bananas.
Example 9.
In example 9, the effect of macro-perforated LDPE bag and micro-perforated
LDPE
bag packaging on the ripening and storability of green bananas was again
determined
under different conditions from example 8. Freshly harvested bananas were
packaged
in commercially used macroperforated LDPE bags (as controls), and
microperforated
LDPE bags according to the invention, in the country of production, packed in
3 and 4
layer cardboard boxes, shipped to Baltimore, Maryland in the United States,
and
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ripened with ethylene through the bags and boxes for 4 days at 60 F. At color
stage
3.5, the temperature of the room was adjusted to 70 F to simulate supermarket
and
consumer conditions. The fruits were monitored for ripening and storability.
One batch of the fruits was pulled out of storage at color stage 3.5,
transported to New
Jersey, and held at 70 F for subsequent color progression, shelf life, and
quality
evaluations. Upon inspection, it was confirmed that under semi-commercial
conditions, the packaging and method according to the invention did not delay
the
ripening process to color stage 3.5, provided highly uniform ripening,
extended the
yellow life of the bananas, did not interfere with the usual taste and flavor
quality of
the bananas, maintained higher firmness during storage post color stage 3.5,
led to 3
to 5 days of extension in shelf life of the bananas, and severely restricted
the
development of sugar spots after their onset.
Example 10.
Example 10 illustrates the applicability of the invention to use for new
commercial
applications, such as the packaging and distribution of single bananas. In
example 10,
ethylene gassed single fingers of bananas weighing approximately 170 grams
each
were packaged individually in micro-perforated bags according to the invention
and
evaluated for storability over 6 days at 68 F. In a separate experiment,
green single
fingers of bananas weighing approximately 170 grams each were packaged
individually in microperforated bags, held at 58 F for 2 weeks to simulate
actual
transit conditions, ripened at 58 F for 4 days with ethylene, and evaluated
for
storability over 6 days at 68 F. In both experiments, package atmospheres of
4.5%
02 and 12% CO2 were achieved on day 6 of holding at 68 F. The control
unpackaged fingers developed sugar spots on day 3 of holding. In comparison,
the
microperforated bags according to the invention had the first signs of sugar
spots on
day 6 of holding. The ripening while delayed with microperforated packaging
was
highly uniform.
Example 11.
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Example 11 illustrates the applicability of the invention for consumer use. A
consumer may purchase loose fruit from a supermarket or convenience store at a
color
stage greater than 3.5, close the fruit in the bag according to the invention,
and
experience the benefit of shelf life extension and thus reduce considerably
the wastage
5 of fruit due to quick quality deterioration at the consumer level.
Fruits from a local supermarket in New Jersey were purchased at color stage 5
and
divided into two lots. The fruits of lot one were packed in bags according to
the
invention and held for 7 days. For comparison, the fruits of lot two were kept
10 unpacked but also held for 7 days. The holding temperature was
approximately 69 F.
While the unpacked fruits developed sugar spots on day 2 of holding, the
fruits in the
bags of the invention had no sugar spots until day 5 of holding. On day 6,
sugar spots
were noticeable on fruits packed in the bags of the invention. The further
15 development of sugar spots was severely restricted and fruits stayed in an
acceptable
form throughout the 7 day holding period. This improved quality coupled with
shelf
life extension is of significant value to consumers of banana fruit. This
example also
demonstrates that this invention can also be extended to the packaging of
gassed fruit.
In that case, it is conceivable that fruit may be ripened under conventional
methods
20 and distributed or marketed in packages according to the invention.
Example 12.
In example 12, freshly harvested green bananas again were packaged in units of
3 lbs.
in the country of production, stored in standard 40 lb. cardboard boxes for 2
weeks at
25 58 F to simulate actual transit conditions, and ripened with ethylene for
4 days at 62
F. At color stage 3.5, the fruits were pulled out of storage and held at 68 F
for
subsequent color progression, shelf life, and quality evaluations.
The example on the left of the photograph shows the state of the fruit at day
6 of
3o holding at 68 F that was packaged in commercially used macroperforated
bags.
These fruits developed sugar spots on day 3 of holding at 68 F. By
comparison, the
example on the right of the photograph illustrates the benefit of the
invention,
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showing no sugar spot development at day 6 of holding at 68 F. This clearly
demonstrates an extension in shelf life of banana fruit by at least an
additional three
days, evidencing a significant benefit to the retailer.
The examples provided throughout have evidenced the advantages and benefits of
utilizing micro-perforation technology in packaging devices for various types
of
perishable food products. In operation, it is the percent open area provided
to the
packages by the micro-perforations which is critical to the successful
establishment
and maintenance of an atmosphere (internal atmosphere of the package) which
allows
for the extended shelf-life of the food products. By way of further
explanation, and as
stated in a previous example, three pounds (31b) of banana fruit was packaged
in a
twelve'inch (12") by seventeen and seven tenths inch (17.7") bag including
forty-two
(42) perforations each having a diameter of one hundred twenty microns (120 ).
This
configuration provided significant advantages in terms of shelf-life and
banana fruit
quality when compared to banana fruit stored within standard, conventional
packages.
Further, this configuration provided a determinable percent open area of the
package
that from the results achieved is an optimal percent open area. From this
example, it
is to be understood that the optimal open area is equal to the area provided
by the 42
holes at 120 divided by the surface area of the bag. Thus, the optimal
percent open
area is generally equal to 1.733 x 10'4%. Therefore, different bag sizes or
micro-
perforation hole size and number may be employed in the present invention and
provide the advantages of the present invention by maintaining this optimal
percent
open area.
It is also determined that an optimal number of holes per pound of banana
fruit is
fourteen (14) holes, having a diameter of 120 , per pound. Thus, a direct
relationship
between the pounds of banana fruit to be packaged and the number and diameter
of
micro-perforations to be included within the package in order to establish and
maintain an optimal internal package atmosphere for assisting in maximizing
the
shelf-life of banana fruit, is provided by the instant invention. For example,
five
pounds (5 lbs) of banana fruit may be stored within a packaging device
including
seventy (70) micro-perforation each having a diameter of 120 . In the
alternative, ten
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42
pounds (101b) of banana fruit may be stored within a packaging device
including one
hundred forty (140) micro-perforation each having a diameter of 120 . It is to
be
understood that the size of the micro-perforations may be similarly adjusted
using the
relationship between optimal percent open area and micro-perforation number
and
diameter.
With respect to the other produce products mentioned above from Example 1
where
approximately half a pound (.5 lb) of shredded carrots, broccoli, cauliflower
and corn
were placed in 7.67" by 13.78" packages (bags) including nine (9) micro-
perforations,
1o each with a diameter of 120 . From this example, it is to be understood
that the
optimal open area is equal to the area provided by the 9 holes at 120 divided
by the
surface area of the bag. Thus, the optimal percent open area is generally
equal to 7.4
x 10-5%. Therefore, different bag sizes or micro-perforation hole size and
number
may be employed in the present invention and provide the advantages of the
present
invention by maintaining this optimal percent open area. With these
determinations
in hand it becomes apparent to one of ordinary skill the art that various
configurations
of the hole size and diameter may be utilized to accomplish the optimal
percent open
area, similar to the determinations provided above, which may assist in
increasing the
shelf-life and maintaining the quality of the various produce products.
With 9 holes of 120 diameter required for every half pound of the produce as
identified above, a relationship between hole number and size and weight of
produce
is readily established. For instance, with one pound (1 lb) of the various
produce
products identified above, the number of holes required is eighteen (18) each
with a
12011 diameter. Such a logical relationship as defined above allows for the
storage of
various weights of produce products within various packages, wherein the micro-
perforations within the packages provide an optimal percent open area for
assisting in
increasing shelf-life and maintaining quality of the produce.
Notably, using the package and method of packaging of the instant invention,
bananas
can be packed in units of 1-401bs. Single bananas can also be distributed in a
similar
manner for special marketing applications, such as the convenience store
market. The
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package and method of the instant invention can also be used by consumers for
extending the yellow life of bananas purchased as loose fruit from
supermarkets,
convenience stores or the like.
The package and method of the instant invention thus provide significant
benefits
over the prior art. More particularly, the banana fruit may be transported
from their
countries of production to the consuming markets of developed countries in a
green,
hard state to withstand the rigors of distribution and handling. Once the
fruit reaches
the destination country, it is ripened to color stage 3.5 before it could be
marketed to
supermarket chains and food service outlets. While fruits at supermarket
shelves are
displayed at color stage 3.5 and beyond, consumers prefer to eat fruit at
color stages 5
to 6.5. In such a practice, banana fruits are delivered to the consumer in a
non-
preferred stage of ripeness. Consumers purchase fruit in clusters and each
cluster may
have 7 to 10 fruits. All the fruits in any given cluster ripen simultaneously
and the
expected shelf life is only 2 to 3 days at room temperature. Thus, consumers
have a
very limited time window to consume bananas at the consumer preferred stages
of
ripeness (color stages 5 to 6.5). On average, consumers eat 25% of the
purchased
banana fruit at the preferred stage of ripeness (5 to 6.5), 50% at non-
preferred stages
of ripeness (<5 or >6.5), and 25% are wasted. Eating banana fruit at non-
preferred
stages of ripeness (under-ripe or over-ripe) leads to consumer dissatisfaction
that has a
strong negative effect on its overall per capita consumption.
The invention set forth herein allows the retailer, food service purchaser or
consumer
to purchase and hold banana fruit at the preferred stage of ripeness for
approximately
5-6 days. Since most of the consumers in the U.S. shop once a week, it is
believed
that the extension of shelf life of banana fruit by this invention will give
consumers an
opportunity to consume fruits at the preferred stages of ripeness throughout
their
shopping cycle. It is further believed that this will lead to improved
consumer
satisfaction, improved per capita consumption and reduced wastage at the
supermarket and household levels.
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Banana suppliers are constantly looking for ways to differentiate their
product from
the competition. New market offerings such as single serve bananas for club
stores,
consumer packages comprising of individual banana fmgers (no clusters) for
quick
service restaurants, and new varieties are being viewed as product
differentiating
processes by major manufacturers and distributors in the banana trade.
However,
quality and shelf life issues have been the challenges thus far for
commercializing
these concepts. This invention helps to consistently deliver a good quality
banana
with improved shelf life in the marketplace and thus should help the banana
companies in product differentiation and eventually brand recognition.
The invention has been described with references to a preferred embodiment.
While
specific values, relationships, materials and steps have been set forth for
purposes of
describing concepts of the invention, it will be appreciated by persons
skilled in the
art that numerous variations and/or modifications may be made to the invention
as
shown in the specific embodiments without departing from the spirit or scope
of the
basic concepts and operating principles of the invention as broadly described.
It
should be recognized that, in the light of the above teachings, those skilled
in the art
can modify those specifics without departing from the invention taught herein.
Having now fully set forth the preferred embodiments and certain modifications
of the
concept underlying the present invention, various other embodiments as well as
certain variations and modifications of the embodiments herein shown and
described
will obviously occur to those skilled in the art upon becoming familiar with
such
underlying concept. It is intended to include all such modifications,
alternatives and
other embodiments insofar as they come within the scope of the appended claims
or
equivalents thereof. It should be understood, therefore, that the invention
may be
practiced otherwise than as specifically set forth herein. Consequently, the
present
embodiments are to be considered in all respects as illustrative and not
restrictive.
